1. Field of the Invention
The present invention relates to an ophthalmic surgery apparatus which treats by irradiating a laser beam to an eye of a patient, and more particularly to a mechanism for delivering the laser beam to a desired position of the eye and for tracking movement of the eye.
2. Description of the Related Art
As an ophthalmic surgery apparatus which treats by irradiating a laser beam to an eye of a patient, for example, a corneal surgery apparatus which uses an excimer laser beam is known. This apparatus ablates a surface of a cornea by irradiating the excimer laser beam so as to remove a diseased portion of the cornea and corrects an ametropia by changing a curvature of the cornea.
In the case that this apparatus is used, an operator makes the patient fix a fixation target with the eye, then aligns an irradiating optical system with the eye so as to be desired condition with observing an alignment target. The alignment is completed, then the operator makes this apparatus irradiate the laser beam so as to ablate determined amount of a desired area of the eye.
Though the patient is made to fix the fixation target with the eye, if an eyeball of the eye happens to move during the alignment or the laser beam irradiation and the movement is confirmed by the operator, then the operator must do the alignment over again once more from beginning, or the operator must discontinue the laser beam irradiation and do the alignment over again.
As described above, doing the alignment over again is a burden to both the patient and the operator because of taking much a long time for its operation or the like. Furthermore, in the case that the eyeball moves often, the burden is much more.
And if the operator does not notice the movement of the eyeball and continues the laser beam irradiation, then the cornea is not ablated so as to be an expected shape, therefore a refractive power of the eye after the operation is influenced thereby.
Furthermore, if the operator is not accustomed to operating the apparatus, then the alignment itself takes much time.